Soil treatment compositions and their use

Abstract

The invention provides aqueous soil treatment compositions comprising water and dissolved ionic water-soluble fertiliser in an amount of at least 10 wt. % and dissolved water-soluble anionic polymer having IV at least 60 l/g and ionic content at least 40 wt. %. Such concentrates can have low viscosity and be pourable and be used as concentrates for dilution in irrigation processes.

1 . An aqueous soil treatment composition comprising water and, in solution, 
 (a) an ionic water-soluble fertiliser in an amount of at least 10 wt. %, and    (b) a water-soluble anionic polymer which has intrinsic viscosity at least 6 dl/g and is formed from water-soluble monomer or monomer blend of which at least 40 wt. % is anionic monomer.    
     
     
         2 . A composition according to  claim 1  in which the polymer (b) has intrinsic viscosity from 8 to 18 dl/g.  
     
     
         3 . A composition according to  claim 1  or  claim 2  in which the polymer (b) has intrinsic viscosity of from 9 to 12 dl/g.  
     
     
         4 . A composition according to any preceding claim in which the polymer (b) is formed from water-soluble monomer or monomer blend comprising at least 50 wt. % anionic monomer.  
     
     
         5 . A composition according to any preceding claim in which the polymer (b) is formed from water-soluble monomer blend comprising from 60 to 80 wt. % anionic monomer and from 40 to 20 wt. % non-ionic monomer.  
     
     
         6 . A composition according to any preceding claim in which the polymer (b) is a copolymer of acrylamide with an alkali metal salt of acrylic acid.  
     
     
         7 . A composition according to any preceding claim in which the polymer (b) is present in an amount of from 2 to 5 wt. %.  
     
     
         8 . A composition according to any preceding claim in which the fertiliser (a) is present in an amount of from 20 to 60 wt. %.  
     
     
         9 . A composition according to any preceding claim which has a viscosity of not more than 4,000 cps, preferably not more than 1,000 cps.  
     
     
         10 . A composition according to any preceding claim which has a viscosity of from 200 to 500 cps.  
     
     
         11 . A composition according to any preceding claim in which the polymer (b) has been added to the composition in the form of a powder.  
     
     
         12 . A soil treatment process comprising irrigating an area of soil with water to which has been added an aqueous soil treatment composition as defined in  claim 1 .  
     
     
         13 . A process according to  claim 12  in which the irrigation is by furrow irrigation, drip irrigation or spray irrigation.  
     
     
         14 . A process according to  claim 12  in which water is pumped through feed ducting and a mixing zone to a spray manifold supplying one or more spraying devices by which the water is sprayed onto a crop area and the aqueous soil treatment composition is metered into the water at or before the mixing zone.  
     
     
         15 . A method for the production of an aqueous soil treatment composition as defined in  claim 1  comprising providing an aqueous solution of fertiliser (a) and mixing with it polymer (b) in powder form.  
     
     
         16 . A process according to  claim 12  or a method according to  claim 15  in which the aqueous soil treatment composition has any of the additional features of  claims 2  to  10 .